This invention relates to a process for forming an upholstered article, and more particularly, to a process for thermal forming upholstered articles using a drawstring which facilitates preassembly of the components of the upholstered article and allows the fabric upholstery covering to be adjusted to remove wrinkles before the fabric and cushions are conformed to the shape of a mold die and adhered together by application of heat, and simultaneously secured to a rigid substrate.
U.S. Pat. No. 4,718,153 (assigned to Steelcase, Inc., the assignee of this invention) discloses a cushion manufacturing process wherein a sculptured, upholstered cushion is prepared by placing a non-preformed sheet of upholstery fabric, a non-pre-formed foam cushion and adhesive means within a die, with the adhesive means disposed between the fabric and the foam cushion, urging the dies together to compress the cushion and force the fabric and cushion to conform to the shape of a die, and injecting hot vapors into the die cavity to cause the cushion to retain the shape of the die. The molded, upholstered cushion is then removed from the die and the excess fabric topping layer and backing sheet are trimmed from the cushion, leaving a narrow web or flange of material which is secured to a chair shell. It would be desirable to provide a thermal forming process for preparing an upholstered article, wherein the need for a separate trimming step is eliminated. Further, it would be desirable to provide such a thermal forming process wherein the fabric can be adjusted and retained in an adjusted state to eliminate wrinkles in the outer fabric upholstery covering.
U.S. Pat. No. 4,732,097 discloses a process for upholstering an object. The process involves the steps of cutting out a flexible piece of fabric having a shape corresponding to one side of an object to be upholstered, stitching onto the border of the fabric an auxiliary thread for providing an overcast passage extending along the border of the fabric, placing a tensioning thread in the passage, covering the front face of the object with the piece of fabric, folding back the border at the edge of the object and applying tension to the ends of the tensioning thread to tighten and fold the border, and locking the ends of the tensioned threads to secure the fabric covering over one side of the object. This patent does not mention applying heat to the fabric, an underlying foam layer and an intervening adhesive layer to shape the fabric and foam and adhere them together.